Middleware is where applications meet infrastructure. Here our consultants write about WebLogic, JBoss EAP, WildFly and Tomcat in real production environments: installing and clustering them, patching, deploying applications and finding out why something stopped working.
Monitoring tools are increasingly going beyond their usual perimeter of just monitoring metrics. Modern tools, like Zabbix, can watch files for any change and raise warning whenever it occurs. An example I found the “Linux by Zabbix agent” template: Computing the /etc/passwd checksum and raise an alert if it changes. In this blog post, I will explain how to get…
Zabbix provides templates easy to setup which do not require any external scripts. As an example, you can check one of my previous blog post on the subject where I monitored a WildFly server. These one includes many items and several discovery rules, but one part is not covered by it: Java Virtual Machine. One can argue that you can…
Zabbix comes with an long list of smart and customizable templates (more than 270). In this blog post, I will explain how to customize these templates and adapt them to your environment’s needs. Macro The first level of customization is the macro. There are several types of macros: For templates, it declares user-defined macros (ie. with $ sign). By looking…
I wanted to test the Zabbix report scheduler. In this blog, I will explain how to do it as well as the different issues I faced (with cause and resolution, obviously 🙂 ). By the way, report scheduler is a Zabbix feature that allow to generate PDF of dashboard sent via email. Install Binaries First step is to install the…
Among the different possibilities for Zabbix storage, one piqued my curiosity: TimescaleDB TimescaleDB is a time series database plugin for PostgreSQL. Joël Cattin already blogged about it here from a general point of view. In this blog post, I will focus on Zabbix setup and visible improvements. Overview As a reminder, my Zabbix was installed with a PostgreSQL database backend,…
JBoss EAP simplifies a lot of server configuration by consolidating all subsystem configurations into a single XML file (standalone.xml or domain.xml). This, however, can expose sensitive information to any user that has access to the configuration files. For example, datasource credentials are by default stored in plain text in the XML file. In this blog I will show you how…
Despite the will of Zabbix to be as automated as possible, some tasks cannot be automated. Nevertheless, Zabbix offers an HTTP-based API which can be used programmatically. This opens the door to huge possibilities in terms of automation. JSON-RPC JSON-RPC is a stateless, light-weight remote procedure call (RPC) protocol. In regard to Zabbix, we simply have to post HTTP requests…
In my previous blog named “Changing Fusion Middleware repository database“, I explained how to move a Fusion Middleware repository database from one host to a new host. During the run of this exercise, I came over an issue with the chghost.sh script failing to start the WebLogic Administration Server with the following error: Investigating on the error, I find out…
On producer side, messages are load balanced across partition based on hashed key. On the consumer side, to ensure that each message is processed by only one consumer within the group, allowing for load balancing, fault tolerance, and efficient utilization of resources in a Kafka consumer application, there is the concept of consumer group. Creation of Consumer Group There is…
In this blog post, I will demonstrate the first few concepts to understand when you want to learn Apache Kafka. Documentation explains it well, but I find that concrete examples give a better feeling of the product and features. Message and Broker Kafka uses the message (also known as event or record) as the unit of data. Optionally, they can…
One of the most common errors while running an application is “out of memory”. And Java is no different besides errors being named exceptions. The exact exception name you might have encountered is: And, in most cases, it is related to Java heap. I will go through a few reminders on what Java heap is. How it works and how…
Among the different packages provided by Zabbix, one arouse my curiosity: Proxy. What is its purpose? When to use it? How to install it? I will cover these in this blog post. Intention There are multiple reasons to use a zabbix proxy in a monitoring infrastructure. The first and foremost is to offload main server from pulling data. Indeed, to…
